A strong undersea earthquake measuring 6.3 on the Richter scale hit eastern Indonesia, although there were no reports of casualties or damage, an official at the country's meteorological agency said on Wednesday.

The U.S. Geological Survey said in a bulletin sent by email that the quake struck the Moluccas islands in the Banda Sea at 1128 GMT and put the magnitude at 5.8.

The Indonesian official said by telephone there was no potential for a tsunami from the quake, with an epicentre 122 km northwest of the town of Saumlaki at a depth of 77 km.

He said residents felt the quake in Saumlaki and the island of Aru.

Joni Sabono, a resident in Saumlaki, said by telephone people had run outside after the quake, although he said there was no serious panic in his area.

"I felt it for 10 seconds, people ran away but there wasn't much shock because we are used to quakes," he said.

Indonesia suffers frequent earthquakes given its location in a highly active seismic zone.

In some remote areas, it takes a long time to assess damage given patchy communications in the sprawling archipelago of more than 17,000 islands.

Indonesia suffered a huge earthquake in December 2004 off Sumatra island, triggering an Indian Ocean tsunami that left some 170,000 people dead or missing in northern Aceh province alone.

Just over a year ago, a powerful quake also devastated an area around the ancient royal city of Yogyakarta, killing more than 5,700 people.